Manufacturing water gas



Original Filed Sept. 27, 1925 gvwizhtoz Frz ZZZl/inHer candescent cokefrom lignite,

Patented Sept. 30, 1930 UNITED STATES PATENT OFFICE I FRITZ WINKLER, OFLUDWIGSHAFEN-QN-THE-RHINE, GERMANY, ASSIGNOR TO I. G. FARBENINDUSTRIEAKTIENGESELLSOHAFT, OF FRANKFORT-ON-THE-MAIN, GER- MANY, A CORPORATIONor GERMANY MANUFACTURING WATER GAS Original application filed September27, 1923, Serial No. 665,221, and in Germany September 27, 1922.

Divided and this application filed May 7, 1928.

ent No. 1,687,118, with the express intention of filing this divisionalapplication.

Fuel gas, such as producer gas, or blue water gas or mixed coal andWater gas has hitherto usually been made from coke in coarse lumps byallowing steam and air, either alternately or jointly, to react with thesaid coke which is in an incandescent state. Pulverulent coal has alsobeen used for producing combustible gases either in the form of a'showerfallin down in a current of air or by means of injection with the air.

According to the usual methods of operation it has not been possible touse'small-sized carbonaceous material, such as refuse coke, coke breeze,coke from lignite, and the like, in the form of grits and small piecesof pea size for making fuel gas.

My invention relates to an improved process whereby small-sized coal orother carbonaceous material can be utilized for making water gas andconsists in charging the finely divided coal on to a suitable grate orsupport in a shaft generator, and blowing air and steam through the saidcoal material alternately with suflicient pressure to bring about astrong agitation in the form of a so-to-say boiling motion of thematerial. On the other hand the blast of gas should not be so strong asto carry away the solid fuel and to blow it out of the generator. A freepassage of the gases is secured and when the layer, or bed, of fuel isnot too low the material is thoroughly mixed while its combustion ,isnot concentrated locally but. well distributed throughout the wholemass, a uniform temperature being thereby established. The ashes do notmelt together. In many cases, particularly when using lignite, the ashesare carried along with'the gases and can be deposited in an adjacentdust chamber.

When the water gas generator is to be set into operation, about onecubic metre of infor example, coke, the grains of whichhave a size ofbetween 4 and 10 millimetres, is introduced Serial N0. 275,974.

by means of the hopper G onto the fireclay layerC resting on the grate Bof about one square metre area. 1000 cubic metres of air are then blownin per hour through the pipe D. The glowing coke is at once agitatedthroughout so that the charge assumes an appearance similar to that of aboiling liquid. The temperature of the coal rapidly increases and freshcoke made from lignite is supplied by the hopper G until the bed of fuelin the producer A has a height of 150 centimetres. By the introductionof the fresh coke the temperature of the fuel bed falls, but uniform ftemperature throughout thewhole mass of fuel is very soon established,as can be determined by a number of suitable thermostats or the likearranged above the grate and Within the body of the generator A. This isdue to the strong agitation of the mass and is also promoted by thehigher weight per unit of volume ofthe cold lignite coke in comparisonwith the glowing coke. While one litre of the glowing coke has a weightof about 500 grams, one litre of the cold coke from lignite has a weightof about 700 grams. This assists the cold coke in sinking down in, andmixing with the' mass of glowing fuel which is continuously maintainedin the strongly agitated a boiling liquid by the gases'continuouslyflowing through the charge of the fuel. The similarity of the charge ofglowing fuel with a boiling liquid is in fact a very striking one. Itmay be demonstrated as follows: The body of the generator A is providedin its upper part with an observation window and with an opening about20 centimetres in diameter which is arranged about 50 centimetres abovethe upper level of the incandescent mass. The amount of air blown in atD is now reduced to about 300 cubic metres per hour. By means of theobservation window it is state above compared with a slightly undulatingmovement which can be observed, especially atthe surface of the 7 fuelbed. When a stone or a lump of iron is thrown into the generator, suchstone or lump rapidly sinks down in the cha ge of coal, down to thegrate C. When a luinp of wet wood is thrown into the generator, it

first sinks down within the charge of the incandescent fuel and thewater vapor escaping from the moist wood throws up a number of smallcoal particles similar to a fountain. After some minutes the wood hasbecome charred and now is carried upwards to the surface of the fuel bedWhere the lump or lumps of charcoal now swim on the surface of the cokebed, just as wood swims on water. When throu h the said opening abovethe charge of co e a current of air is blown in an oblique direction onto the surface of the charge, the air current throws up waves just aswould be the case with water. It will be obvious from these explanationsthat the charge of fuel in my generator has a very strikin behavior.Though it is continuously whirle up and down, the whole mass is rathercompact, much more than would be the case, for example, when allowing afine powdery material to fall down in a stagnant or streaming mass ofgas. Accordingly each particle of fuel is brought into intimate contactwith the gas blown in from below, but not with so much gas that an undueremoval of heat and dilution of the reaction product between the gas andthe fuel would be caused. Owin to the intense agitation of the fuelpartic es, the entire charge of fuel has a Very uniform temperature. Theslags formed sink down onto the grate similar to the lump of iron in theabove described experiments. The fine ashes of the lignite coke are forthe most part carried away by the gas current and may be separated fromthe gases in any suitable manner after they have left the generator.Steam may be employed as the gasifying agent alternately with air in theabove arrangement. It is characteristic of my invention that the entirebed of fuel is kept in continuous agitation by means of the gas currentblown through the charge from below, whether this is air or steam orother gasifying medium and that this state of continuous agitation ismaintained merely by the gas current and without any mechanical means.

My invention will be more fully explained with reference to the annexeddiagrammatical drawing showing a vertical section which explains themanufacture of water gas from lignite coke, but the invention is notrestricted to this example;

Lignite coke is placed in a cylindrical shaft water gas generator Awhich is conically reduced at its botttom and there contains, as agrate, a perforated plate of fireclay B carrying a layer C of about twoinches thickness of pieces of fireclay of about nut size. The coke isignited and air blown in from below through the inlet pipe D first at amoderate pressure, which gradually is raised until the particles of cokecommence to execute a vigorous whirling movement so that the massassumes an appearance of boiling. The gases of combustion or air blastgases containing finally up to 30 percent, by volume, of carbon monoxidand 2 per cent of carbon dioxid, take the light ashes along, removingthe greater part of the ashes from the generator, and then are conveyedthrough a dust chamber where the ashes are caused to deposit. This dustchamber may be of the usual form and requires no detailed description,and has also been omitted from the drawing. When a temperature of about1100 C. is reached, the supply of air is cut off and steam which isadmitted through pipe E is blown through the incandescent coke at asimilar pressure, or speed, to maintain the strong agitation of the finecoke material. Blue water gas is thereby formed approximately composed,by' volume, of 43 per cent of carbon monoxid, 45 per cent of hydrogen,2.5 per cent of carbon dioxid and 9.5 per cent of nitrogen, and which isfree from oxygen and methane. After the temperature has fallen in thesteaming period, the coke is reheated by again blowing air through andthe operations are alternately repeated, the gases produced in the twoperiods being withdrawn separately through the outlet pipes F and Fshown in the drawing. Fresh coke is supplied when necessary in aconvenient manner from the hopper G. H is a discharge opening throughwhich ashes may be removed, if necessary. Small-sized lignite itself maybe used instead of lignite coke, or small-sized coke, or hard or softcoal.

What I claim is 1. The process of manufacturing water gas in a generatorhaving a bed of small-sized, incandescentsolid carbonaceous material,which comprises blowing air and steam through said material alternatelywith sufiicient speed to establish a boiling action in the material,thereby causing gasification thereof by reaction between theincandescent material and the air and steam.

2. The process of manufacturing water gas in a generator having a bed ofsmall-sized, incandescent coke made from lignite, which comprisesblowing air and steam through said coke alternately with suflicientspeed to establish a boiling action in the coke, thereby causinggasification thereof by reaction between the incandescent coke and theair and steam.

In testimony whereof, I aflix my signature.

FRITZ WINKLER.

